The present invention relates to an exposure technique, for example, relates to technology useful for a transfer technique etc. of circuit patterns in manufacturing processes of semiconductor integrated circuits etc.
When design rules for circuit elements and wirings become on the order of submicrons as high integration of semiconductor integrated circuits advances, in a photolithography process where circuit patterns on masks are transferred onto semiconductor wafers by using lights of g-line and i-line etc., the reduction of accuracy of circuit patterns transferred onto wafers becomes a serious problem. As a measure for improving such a problem, a phase shift technique preventing reduction of contrast of the projected image by varying phases of light transmitted through the mask is proposed. For example, Japanese patent application laid-open No. 173744/1983 discloses a phase shift where a transparent film is provided on one side of a pair of transmission domains between which a shielding domain is inserted, and a phase difference is produced between lights transmitted through the two transparent domains in the exposure, whereby the interference lights weaker each other at the point on the wafer which would become a shielding domain originally (hereinafter referred to as xe2x80x9cLevenson typexe2x80x9d or xe2x80x9ccomplementary type phase shift methodxe2x80x9d).
Also, Japanese patent application laid-open No. 67514/1987 discloses a phase shift technique where after a part of the shielding domain of a mask is removed and a fine open pattern is formed, a transparent film is provided on either of the open pattern or the transmission domain existing in the vicinity thereof, and a phase difference is produced between the light transmitted through the transmission domain and the light transmitted through the open pattern, whereby the amplitude distribution of lights transmitted through the transmission domain is prevented from spreading laterally (hereinafter referred to as xe2x80x9csubshift type phase shift methodxe2x80x9d).
Japanese patent application laid-open No. 140743/1990 discloses a phase shift technique where a phase shifter is provided on a part of the transmission domain of the mask and a phase difference is produced in the transmission lights, thereby the phase shifter boundary is emphasized (hereinafter referred to as xe2x80x9cedge emphasized type phase shift methodxe2x80x9d).
However, any of these relates to the improvement of phase shift techniques on the experimental level, and does not fully consider the problems in the case of application to actual devices on the mass production level in which complicated patterns are mixed.
Accordingly, an object of the present invention is to provide a phase shift exposure technique where mask production is easy.
Another object of the present invention is to provide a phase shift exposure technique suitable for exposure of fine patterns in submicron units.
Another object of the present invention is to provide a reduced projection exposure method to enable exposure of various and fine patterns in the manufacturing process of semiconductor devices or semiconductor integrated circuit devices.
Another object of the present invention is to provide a phase shift exposure technique which does not produce unnecessary patterns.
Another object of the present invention is to provide a phase shift exposure technique which produces accurate patterns even at the ends of periodic patterns.
Another object of the present invention is to provide a phase shift exposure technique having a high integration density.
Another object of the present invention is to provide a phase shift exposure technique to enable the production of complicated patterns.
Another object of the present invention is to provide a phase shift exposure technique suitable for the manufacture of a DRAM.
The foregoing and other objects and novel features of the present invention will become apparent from the description of the present specification and the attached drawings.
A brief explanation of one of the summaries of the present invention, to attain such objects, is as follows.
That is, the constitution of the present invention is for carrying out the reducing projection exposure on the end of the mask pattern domain having a definite mode or the boundary of the mask pattern domain having plural modes using a phase shift mask where a prescribed correction pattern is provided.
According to the above constitution, as the end effects etc. cancel each other by the above-mentioned correction pattern, the various and fine patterns can be exposed.
The foregoing and other summaries of the invention included in the present application are itemized as follows.
1. In the manufacturing method or the exposure method for semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in ultraviolet or deep ultraviolet domain (If it has coherence, it need not be monochromatic light, and this applies also in the following items.) is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture (it may be an equi multiplication system. Also, it may be the combination reduced optical system being composed of a lens system and mirrors, and the same applies also in the following items.) so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) a main opening region like a band having a constant width and corresponding to a line pattern isolated at least on one side; and
(b) a plurality of supplementary opening regions like dots or broken lines not forming their own patterns and having phases opposite to the main opening region and provided along one side of the main opening region and close to it spaced by regular intervals.
2. In the manufacturing method or the exposure method for semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in ultraviolet or deep ultraviolet domain (not limited to ultraviolet ray, and the same applies in the above and successive items) is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) a main opening region corresponding to a pattern whose featuring conversion length is comparable with or not more than the wavelength of the exposure light; and
(b) at least one supplementary opening region not forming its own pattern and corresponding to parts where the patterns for the bright parts focusing on the wafer are liable to become thin by the interference effect of light when the main opening region is exposed as it is, the supplementary opening region having the same phase as that of the main opening region and continuing to the vicinity of the main opening region or to that parts.
3. In the manufacturing method or the exposure method for semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) one corner region of a shifter domain which is a light transmission region where the shifter domain and a mask substrate exposure domain are directly adjacent to each other so that the shifter domain may become convex globally; and
(b) at least one local shifter loss part having the same phase as that of the mask substrate exposure region and not forming its own pattern and installed on the corner region of the shifter domain corresponding to parts where a dark pattern corresponding to the shifter domain focusing onto the wafer is liable to project or thicken undesirably by the interference effect of light when it is exposed intact.
4. In the manufacturing method or the exposure method for semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) a plurality of band-shaped main opening regions with phases reversed alternately, corresponding to a plurality of linear patterns arranged with a constant width and interval; and
(b) a band-shaped dummy opening region being installed along a main opening region of one end of the plurality of main opening regions, with approximately equal intervals and forming its own patterns and having the reversed phases to that of the main opening region of one end with approximately equal width.
5. In the manufacturing method or the exposure method for semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) a plurality of band-shaped main opening regions with phases reversed alternately, corresponding to a plurality of linear patterns arranged at a constant width and interval; and
(b) a band-shaped wide main opening region being installed along a main opening region of one end of the plurality of main opening regions with approximately the same interval as that of the main opening regions and having a larger width than the main opening regions so that it has the same width as that of the main opening regions at the exposure state and forming its own pattern having a reversed phase to that of the main opening region of one end.
6. In the manufacturing method or the exposure method for semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transformed onto the wafer,
wherein the mask comprises:
(a) the first phase shift mask pattern group according to the first mode; and
(b) the second phase shift mask pattern group according to the second mode.
7. In the manufacturing method or the exposure method for semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) first and second main opening regions having approximately equal complicated configurations and arranged closely and having phases reversed to each other.
8. In the manufacturing method or the exposure method for semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) an approximately square phase shift mask pattern group forming a plurality of approximately square patterns being arranged closely in the oblique direction.
9. In the manufacturing method or the exposure method for semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and wherein the luminous flux passing through mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) the first and second main opening regions arranged closely and having the same phase;
(b) a supplementary opening region provided to couple the first and second main opening regions and having the same phase as those of the first and second main opening regions over their full ranges; and
(c) a phase shift region having a phase reversed to that of the first and second main opening regions and provided at the center of the supplementary opening region so that the focused patterns on the wafers corresponding to the first and second main opening regions may be separated at the exposure.
10. In a mask for manufacturing or exposing semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) a band-shaped main opening region having a constant width and corresponding to a linear pattern isolated at least on one side; and
(b) a plurality of supplementary opening regions of dot shape or broken line shape being installed along one side of the main opening region closely with a constant spacing therefrom and having reversed phases to the main opening region and not forming their own pattern.
11. In a mask for manufacturing or exposing semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) a main opening region corresponding to a pattern whose featuring conversion length on the wafer is comparable with or not more than the wavelength of the exposure light; and
(b) at least one supplementary opening region not forming its own pattern and corresponding to parts where the patterns for the bright parts focusing on the wafer are liable to become thin by the interference effect of light when the main opening region is exposed as it is, the supplementary opening region having the same phase as that of the main opening region and continuing to the vicinity of the main opening region or to the parts.
12. In a mask for manufacturing or exposing semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) one corner region of a shifter domain which is a light transmission region where the shifter domain and a mask substrate exposure domain are directly adjacent to each other so that the shifter domain may become convex globally; and
(b) at least one local shifter loss part having the same phase as that of the mask substrate exposure region and not forming its own pattern and installed on the corner region of the shifter domain corresponding to parts where a dark pattern corresponding to the shifter domain focusing onto the wafer is liable to project or thicken undesirably by the interference effect of light when it is exposed intact.
13. In a mask for manufacturing or exposing semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) a plurality of band-shaped main opening regions with phases reversed alternately, corresponding to a plurality of linear patterns arranged with a constant width and interval; and
(b) a band-shaped dummy opening region being installed along a main opening region of one end of the plurality of main opening regions, with approximately equal intervals and forming its own patterns and having reversed phases to that of the main opening region of one end with approximately equal width.
14. In a mask for manufacturing or exposing semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) a plurality of band-shaped main opening regions with phases reversed alternately, corresponding to a plurality of linear patterns arranged with a constant width and interval; and
(b) a band-shaped wide main opening region being installed along a main opening region of one end of the plurality of main opening regions, with approximately the same interval as that of the main opening regions and having a larger width than the main opening regions so that it has the same width as that of the main opening regions at the exposure state and forming its own pattern having a reversed phase to that of the main opening region of one end.
15. In a mask for manufacturing or exposing semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) a first phase shift mask pattern group according to a first model and
(b) the second phase shift mask pattern group according to a second mode.
16. In a mask for manufacturing or exposing semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) an approximately square phase shift mask pattern group forming a plurality of approximately square patterns being arranged closely in the oblique direction.
17. In a mask for manufacturing or exposing semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) first and second main opening regions arranged closely and having the same phase;
(b) a supplementary opening region provided to couple the first and second main opening regions and having the same phase as those of the first and second main opening regions over their full ranges; and
(c) a phase shift region having a phase reversed to that of the first and second main opening regions and provided at the center of the supplementary opening regions so that the focused patterns on the wafers corresponding to the first and second main opening regions may be separated at the exposure.
18. Method of transferring patterns of a photo-mask onto a substrate using light rays and forming patterns onto the substrate, wherein the patterns are formed by combining a system of forming different patterns with lights of the same phase and a system of forming different patterns with lights of the reverse phase.
19. A mask for exposing patterns in a method of transferring patterns of a photo-mask onto a substrate using light rays and forming patterns onto the substrate, wherein the patterns are formed by combining a system of forming different patterns with lights of the same phase and a system of forming different patterns with lights of the reverse phase.
20. In the manufacturing method or the exposure method for semiconductor devices or semiconductor integrated circuit devices where monochromatic exposure luminous flux having a constant wavelength and being coherent or partially coherent in the ultraviolet or deep ultraviolet domain is irradiated on one mask on which prescribed enlarged patterns are formed, and the luminous flux passing through the mask is reduced and projected by the reducing lens system having a constant numerical aperture so that the desired reduced patterns corresponding to the enlarged patterns on the mask may focus onto the resist film of a treated wafer on one of whose main surfaces is formed the photo-sensitive resist film, thereby the reduced patterns corresponding to the enlarged patterns on the mask are transferred onto the wafer,
wherein the mask comprises:
(a) first and second main opening regions arranged closely and having phases reversed to each other;
(b) a first supplementary opening region provided to couple the first main opening region and having the same phase as that of the first main opening region over its full ranges; and
(c) a second supplementary opening region having the same phase as that of the second main opening region and coupled with the first supplementary opening region nearly at the center between the first and second main opening regions so that the focused patterns on the wafers corresponding to the first and second main opening regions may be separated at the exposure.